What it is the volume of Sean's replica?

Question

He makes a replica of the Washington monument. He simplifies it so that the structure can resemble a square prism on the bottom and a square pyramid on the top. The total height of the replica is 24 in. The total height of the pyramid at the top is 4 inches. The length of one side of the square base of the replica is 3 in.

Answer 1

V_base = (3²)(24)

V_pyramid = (1/3)(3²)(4)